Automatic blasting fuse igniting device



Dec. 15, 1936.

J. F. WIGGERT AUTOMATIC BLASTING FUSE IGNITING DEVICE Filed April 9, 1955 2 Sheets-Sheet. l

Snnentor ,Lim E www Bg u Dec. 15, 1936. 1 F, WIGGERT 2,064,706

AUTOMATIC BLASTING FUSE IGNITING DEVICE Filed April 9, 1935 2 Sheets-Sheet 2 EN i z3 Snventor Patented Dec. 15, 1936 UNITED STATES PATENT GFFICE AUTOMATIC BLASTING FUSE IGNITING DEVIC 1 Claim.

The present invention relates to ignition devices adapted particularly for igniting blasting fuses and the like.

An object ci this invention is to provide a fuse igniting device which is automatic in action in that the fuse is ignited by merely inserting the fuse in the device.

Another object is to provide an igniting device with circuit closing contacts adapted to be closed by the fuse itself as it is inserted in the device, and with igniting electrodes so placed that they may serve as a stop to determine the correct positioning of the fuse when inserted and at the same time dispose the gap between the electrodes across the exposed powder at the end of the fuse to insure proper igniting of the fuse.

A further object of the invention is to conserve consurnption of electrical energy by closing the circuit only when the fuse is in place and during the time oi actual igniting of the fuse, and wherein the fuse will almost instantly become ignited when inserted and seated in the device.

Another object of the invention is to provide a blasting fuse igniting device which is entirely automatic in operation with the exception that the fuse must be manually inserted and withdrawn relative to the device, and to provide a device which is capable of Very high speed operation as the only limit of its capacity is the dexterity of the operator.

With the foregoing and other objects in View, the invention will be more fully described hereinaiter, and will be more particularly pointed out in the claim appended hereto.

In the drawings, wherein like symbols refer to like or corresponding parts throughout the several views,

Figure l is a vertical section taken through an igniting device for blasting fuses constructed according to the present invention.

Figure 2 is a diagrammatic plan view of the circuit and included parts of the device.

Figure 3 is a detail enlarged top plan View of the circuit closing contacts and the spark producing electrodes with their mountings.

Figure 4 is a longitudinal section taken through the same on the line 4-4 of Figure 3, and

Figure 5 is an inner end elevation of the same, looking toward the electrodes.

Referring now to the drawings which show one embodiment of the invention, I designates a casing of suitable size and material for housing the igniting device. The lower part of the casing carries an induction coil |I having a pole piece I2 at its upper end opposite which is disposed a vibrating contact I3 carried upon a supporting post or clip I4 mounted on the upper end of the induction coil II. The vibrating contact I3 has near its outer end a contact piece arranged opposite a fixed contact piece which is carried on an adjustable arm I5. The arm I is mounted at one end on a post I6 on the upper end of the induction coil I I and at its other end is adjustably disposed relatively to the vibrating arm I3 by means of a threaded post I'I and an adjustable nut I8. Thus, the action of the vibrator may be adjusted to suit conditions of use. A partition or supporting plate I9 is disposed in the upper part of the casing I0, above the induction coil I| and provides a support for certain parts hereinafter described -which are located in a compartment or chamber above the plate I9.

Suitably mounted upon the upper side of the plate I9 at the forward side of the casing is a bracket 20 which may be of sheet metal suitably bent to provide a, vertical web through which is mounted a fuse socket 2|.

The socket 2| may be in the form of a tube proportioned to receive the end of a fuse 22 and which is externally threaded to receive a pair of lock nuts 23 adapted to bind against the opposite sides of the bracket web 20 and hold the tube 2| in adjusted position on the bracket. The socket 2| is provided at its inner end and in its upper side with a recess 24 adapted to receive the downwardly arched portion or loop 25 of a spring contact arm 26 carrying a, contact piece 21 at the upper end of the loop 25. The contact piece 21 is adapted to be raised by the arm 26 into engagement with a xed contact piece 28 carried upon a, fixed arm 29. The upper end of the bracket 20 is overturned to provide a. support or rest upon which the contact arms 26 and 29 are mounted with suitable insulation 30 therebetween, clamping screws 3| engaging through the inner ends of the arms` 26 and 29 and the insulation 3U and also engaging in the upper part of the bracket 20 to hold the parts rmly in relative position. The longitudinal adjustment of the fuse socket or tube 2| disposes the downward projection or loopy 25 of the contact arm in the path of the fuse 22 when inserted in the socket and provides a direct circuit closing means operable automatically by the insertion of the fuse itself.

The bracket 20 is also used for supporting a. pair of electrodes 32 and 33. These electrodes are in the form of bars threaded at their forward ends and suitably secured by lock nuts or the like, as shown, to the bracket 20, the electrode 32 being shown in the present instance as being grounded to the bracket 20 and also serving as a binding post to receive a high tension circuit wire 34 while the electrode 33 is shown as being insulated from the bracket 28 by insulation 35 and serving as a binding post for the opposite wire 36 of the high tension circuit. The movable contact 2G disposed above the socket 2l is grounded through the bracket 2Q while the xed contact arm 29 is insulated from bracket '25J and provided with a binding post Sl to which is attached a wire 38 leading from a battery 39 or other suitable source of electric energy and disposed in the low tension circuit. The battery 3e is connected by a wire 4G to the adjustable contact arm l5 of the induction coil l l. The vibrating7 contact arm I3 of the induction coil is connected to the primary Winding 4l which is grounded, as shown by the wire 34, the latter leading to the electrode 32 and to the movable contact arm 25. The secondary winding 42 of the induction coil is grounded to the vvire 34 and at its other end is connected by the wire 3G to the opposite electrode 33, as clearly shown in Figure 2.

The electrodes 3.5? and 33 are preferably disposed at opposite sides of the fuse socket 2i and extend backwardly in the casing IS a distance greater than the inner end of the socket 2l. The rear ends of the electrodes 32 and 33 are extended inwardly toward each other and toward the end of the socket tube 2i with the extremities of the electrodes spaced apart to provide a spark gap E3 disposed in transverse alinement to the axis of the socket 2! so that when the fuse 22 is inserted in the socket it cornes into contact with the spaced ends of the electrodes 32 and 33 which not only stop the movement of the fuse and determine the correct position thereof in the igniting device, but also dispose the spark gap 43 across the exposed end of the fuse to ignite the powder thereof. The socket 2l and the projection 25 of the movable contact 25 are so proportioned that as the fuse 22 is inserted in the socket it engages the projection 25 and lifts the contact piece 21 into engagement with the fixed contact 28 so as to close the primary circuit. This immediately energizes the induction coil ll and produces the spark across the gap 43. The inward movement of the fuse 22 practically simultaneously closes the contacts 21 and 28 and brings the end of the fuse 22 against the electrodes 32 and 33.

Thus, the fuse 22 is ignited automatically and almost instantly it is seated in the end of the socket 2l. The casing ID is provided with a suitable opening in one side to register with the socket 2| so that the fuse 22 may be quickly inserted in the socket, ignited and withdrawn therefrom without any unnecessary delay and with great speed. With this device it is unnecessary to have the primary circuit closed for any appreciable length of time and consequently the life of the battery 39 is prolonged indefinitely on account of the small consumption of current, and the induction coil and other parts of the device are also kept in proper condition as the current is not maintained through the contacts for any appreciable length of time and consequently the heating up of the contacts and corrosion thereof is avoided.

It is obvious that various changes and modifications may be made in the details of construction and design of the above specifically described embodiment of this invention without departing from the spirit thereof, such changes and modifications being restricted only by the scope of the following claim.

What is claimed is:-

A blasting fuse igniting means comprising a casing, an induction coil within the casing, a partition extending across the casing dividing the casing into a coil chamber and a fuse igniting chamber, an upstanding support secured to said partition in said fuse chai: ber, a fuse holding tube extending through said support, said fuse chamber having an opening alining with the tube, means for securing said tube to said support, a pair of spaced apart electrodes disposed in confronting relation to the inner end of said tube, means for securing said electrodes to said support on each side of said tube, means for connecting said electrodes to one side of said coil, said tube having a notch therein, and a spring pressed switch carried by said support and having a portion thereof projecting into said notch whereby to close the switch upon insertion of a fuse into said tube, and means for connecting said switch to the other side of said coil.

JOHN F. VVIGGERT. 

